This invention relates to a microfilm typewriter e.g. a printer for optically printing small characters, numerals and symbols one by one.
Typewriters now in use are to print characters, numerals and symbols large enough to be read directly by naked eyes, and most of them are adapted to accomplish mechanical printing using types. Recently, a very large amount of information has come to be handled and, for the purposes of storing and using such information, microfilm systems have come into wide use. However, ordinary microfilm systems now in use are to make reduced copies of printed, copied, handwritten or typewritten documents by the employment of a photographic camera.
It would be very convenient if a micro character could be added to microfilm data when required. Recently, in offices, hospitals and so on, it is highly desired to realize such apparatus or apparatus capable of printing micro characters directly on a microfilm from the beginning, that is, the so-called microfilm typewriter. Such apparatus is almost impossible to realize with conventional typewriters partly because of a difficulty in the making of extremely small types required therefor and partly because of possible deformation of characters, wear of the type face and so on.
To avoid such a mechanical printing method, it is theoretically possible to employ such an optical printing method that a pattern of a character is optically printed by leading the pattern to a recording paper through a bundle of optical fibers. Also with this method, it is very difficult to transmit a very small micro character through the bundle of optical fibers. Another conventional printing apparatus of the type optically printing characters one by one is such as a photo-typegraphic composing machine for producing a printing plate, but printed characters, numerals and symbols cannot be read immediately after printed.
U.S. Pat. No. 3,207,051 sets forth apparatus in which characters can be optically printed one by one and the printed characters can be read. With this apparatus, however, the characters to be printed are relatively large and ultraviolet-ray sensitive material requiring thermal development is used as a recording paper, so that a development process is indispensable, making it very difficult to read printed characters at the printed position during printing.
An object of this invention is to provide a microfilm typewriter with which it is possible for the operator to rapidly and distinctly record very small characters, numerals and symbols one by one while checking for an error in the printed characters, numerals and symbols and in the arrangement thereof.
Another object of this invention is to provide a microfilm typewriter which enables the operator to immediately read a printed character, numeral or symbol together with those already printed in the vicinity of the printing position, and which is relatively simple in construction and small in size and has a long life.